Maximum weight

[Toshbins]

Yes it is an auto.

Much nicer to drive when towing just makes you a bit Lazy

Check that you don't need an additional transmission oil cooler. My last Jeep would have needed one for extended towing.

[Bookend]

Having wrecked a Land Cruiser auto box with 140k miles of towing I learnt the hard way.

With the Hilux you just keep it in 4 and not D to prevent the torque converter locking and all is ok.

I had the same issue as you with a Jeep bit thanks for the pointer.

[sabconsulting]

Having wrecked a Land Cruiser auto box with 140k miles of towing I learnt the hard way.

With the Hilux you just keep it in 4 and not D to prevent the torque converter locking and all is ok.

I had the same issue as you with a Jeep bit thanks for the pointer.

This is interesting. I haven't owned many automatics, though I've driven them a lot in the US.

Reading the US forums - they swear by the reliability and strength of their auto boxes, then another thread is full of people whose auto box has dumped its ATF all over a Colorado freeway.

My interpretation is that it is overheating that kills these things - dragging a heavy load up several thousand feet of incline at speed. This seems bourn out by the addition of transmission oil coolers to heavier duty vehicles. Given the epicyclic gears are either stationary or moving freely (at least the annular gear) and nothing in between (when not shifting) I would expect most of the killer heat to build up in the torque converter. So I would imagine that would be worse when the torque converter is unlocked and therefore slipping and therefore generating heat.

So I understand shifting into 4 to prevent the gearbox continually hunting and possibly wearing out the lock-up clutch trying to lock and unlock the torque converter, wouldn't this also allow the torque converter to generate lots of heat?

The above is just my theory so may be completely wrong - But I am interested to learn even if I may never end up towing with an automatic.

Steve.

[Bookend]

I can't say I fully understand the workings of an auto box but I am just going from the owners manual for both the Land Cruiser and Hilux say and also backed up by the dealers.

I never read it with the Land Cruiser until it was too late.

I had a Grand Cherokee that had a tow / haul button which did the same thing electronically.

[sabconsulting]

I do like the tow / haul button on US trucks. Though I tend to use them on descents more than ascents - on descent they will change down on overrun to apply engine braking and change down much aggressively on overrun when you touch the brakes. Having had a bad case of brake fade crossing the Sierra Nevadas once I am much more cautious about these things.

I think tow / haul mode is less about reducing the risk of transmission overheating and more about improving the driveability uphill (it stays in lower gear rather than having that awful delay as you apply more and more throttle and nothing seems to happen) and improving the engine braking downhill for safety.

Rather perversely I always enjoyed the effect of predicting exactly how much throttle to apply at any time to get the transmission to change into the gear I wanted - applying a quick change in throttle to fool it into an up or down shift. Stupid really as the whole idea is you just let it do its thing - maybe it was just the smug enjoyment of tricking it into doing what I want

Steve.